A B777 was dispatched in non compliance with one cabin portable oxygen bottle missing a mask.

Attributes
ACN	548580
Time
Date	200204
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B777 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground : maintenance ground : parked
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
ASRS Report	548580
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance maintenance problem : improper documentation non adherence : published procedure non adherence : far non adherence : company policies
Independent Detector	other other : gnd 1
Resolutory Action	none taken : detected after the fact
Consequence	other other
Factors
Maintenance	contributing factor : schedule pressure performance deficiency : non compliance with legal requirements performance deficiency : logbook entry performance deficiency : inspection performance deficiency : scheduled maintenance
Supplementary
Problem Areas	Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

While accomplishing the interior portion of the 'a' check on B777 at ZZZ on apr/xa/02, there may have been the possibility that a mask on one portable oxygen bottle was missing at one location in the B777. I do not recall it being missing, which is why I signed for that part of the 'a' check, but it is possible it may have been missed.

Original NASA ASRS Text

Title: A B777 WAS DISPATCHED IN NON COMPLIANCE WITH ONE CABIN PORTABLE OXYGEN BOTTLE MISSING A MASK.

Narrative: WHILE ACCOMPLISHING THE INTERIOR PORTION OF THE 'A' CHK ON B777 AT ZZZ ON APR/XA/02, THERE MAY HAVE BEEN THE POSSIBILITY THAT A MASK ON ONE PORTABLE OXYGEN BOTTLE WAS MISSING AT ONE LOCATION IN THE B777. I DO NOT RECALL IT BEING MISSING, WHICH IS WHY I SIGNED FOR THAT PART OF THE 'A' CHK, BUT IT IS POSSIBLE IT MAY HAVE BEEN MISSED.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.